I think the impact of score on gameplay tends to be significantly overrated. Folks don't horde and grab bases for score, especially not in fighters. Competing with 20 other guys for a single kill doesn't really help your score.
It's just like ENY limits generally never made a significant number of players switch to the outnumbered side (not even when it was 1h), even though they complain a lot about not being able to fly 'their' ride. At worst (best?) they just log off instead or stay in tower waiting for someone else to log.
For many players, contributing to a base capture is their main (and sometimes only) way to get a small share of "victory". They often have little means of winning any other way (Most folks that complain here about hording are way above the average pilot in skill level.) A battle for base that doesn't end with a capture is a lost battle. Flying together increases their chance for a victory. Winning the war is the ultimate victory. Kinda easy to say they should cherish the fight and not the grab when you are not the one dying 9 out of 10 times in regular, 'noble' combat
And defending the base just does not give them the same feel of accomplishment. No big fanfare telling everybody "A44 has been defended by Rooks". Furthermore, defending is reactive, and ppl want to have the initiative. That's why you never read "I'm tired of capturing bases, who wants to defend one with me?", but frequently the opposite.
It's mostly about psychology, and relatively little about score or perks...